Ever since Chekov was sent down to scope out a new planet with the team, he hasn't been acting right, almost like an animal. So naturally McCoy is put in charge of his health and strange behaviour; which just baffles and annoys the doctor at first... But then Chekov's symptoms take a very different turn.

They had been on shore leave now for around two days, everyone was getting plenty of R&R and there had been no further discussion on the relationship between the doctor and Russian helmsman aside from the few comments of congratulations from wandering members who occasionally passed the couple who were sitting under a tree in the wide, vibrant meadow that set a light feeling of contentment through everyone as the sun warmed their face. Hell, even Spock showed signs of relief as he sat opposite the captain, kirk absently picking at grass as he spoke with his science officer, a grin over his face.

"When do you think, Mr Spock and Captain Kirk plan on telling the rest of the crew about their relationship" the southerner mocked the previous words from the Vulcan to Chekov who chuckled and sat up closer into the older man's chest. His back pressed against the warmth of the doctor's body.

"Hopefully soon, Leonard, surely zey cannot hide it any longer" he commented with a cheeky grin. The look of mischievous youth made McCoy's heart hurt with a lovely little pain and he squeezed his arms tighter round the Russian, burying his face into the light curls.

"You seem a lot better, are you in much pain anymore?" Chekov asked, appreciating the secure sense of strength around him.

"Not really, I've got nice and fixed up, this shore leave us just what the doctor ordered"

Chekov laughed, leaning back to look up at McCoy with wide green eyes that reflected the stain glass patterns that threaded through the leaves of the tree onto the luscious ground. As if any of that happened before with the demon crawling about in Chekov's head. It was like some bad dream now. McCoy shuddered just thinking about what could have happened. He didn't have to think much longer because Uhura came over carrying drinks.

"I got you two a drink" she smiled and they returned the gesture, gratefully collecting the smooth glass into their hands.

"Thanks Uhura" McCoy nodded his head as Chekov took a gulp.

"спасибо" Chekov muttered with a grin.

"нет проблем" she answered and his eyes lit up with a laugh as she moved away to offer drinks to the others.

"Kind of makes me feel bad for not knowing any of them Russian words" McCoy admitted, taking a swig only to have Chekov move away to sit in front of him, cross legged.

"Then I must teach you some! Vould you like to?" he sat up straight beaming. How could the doctor say no to that face of pure, unadulterated sweetness?

"Sure, go for it"

About half an hour later McCoy was still having difficulty wrapping his tongue around the accent within each word. But never was Chekov disappointed or offended, the young man had never looked more delighted in his life.

"Not quite Leonard, the tone is a bit softer and more emphasis on the 'ya'!"

"Ochen Pri…PriYATna"

"мне тоже!" Chekov replied with a giggle and the southerner rolled his eyes.

"Now what does that mean?"

"Me too, in reply to your 'pleased to meet you'"

McCoy playfully gave a sceptical look at his lover who copied the expression with wide eyes and pouted lips that broke the southerner's demeanour and made him laugh.

"I think that is enough Russian for today, Pasha"

The green eyed nineteen year olds eyes widened and he leant back.

"You…you called me Pasha?!"

"…Oh shit, sorry, is that offensive? Sulu reckoned I should call you it…isn't it some kind of-"

He couldn't finish because Chekov was kissing him but that was always a perfectly legitimate reason for not being able to finish a sentence.

"I'll take that as a 'nyet' you're not offended?"

"да" Chekov answered and pushed the doctor back onto the grass, kissing him tenderly.

Later on in the evening when everyone had returned to their quarters on the planet for the night; small luxurious cabins dotted around a rural area, McCoy and Chekov had their own and the doctor was lying in bed reading when Chekov came round the doorway only in boxer shorts.

"Hey Pasha" the doctor smirked as the Russian came over to him shyly. "Hey you okay?" the southerner added as Chekov didn't meet his eyes for a moment.

"Leonard…I vas…getting ready for ze night and…I feel like…I did before…like vhen I had been affected by zat thing on ze planet"

McCoy didn't answer for a second as a slow panic drew over his lungs like white hot lava moving slowly and causing the man to drop his book and sit up.

"What kind of symptoms?"

"I have been kind of…rough around people again and…vell…I am kind of…" he mumbled the last of that sentence in his native tongue.

"I don't recall doing that in Russian one on one earlier" McCoy tried a nervous grin but the twenty year old only gulped fearfully.

"O-Obsessed with you" he whispered, hanging his head and moving away from the bed to stand near the wall.

"Like…animal obsessed? Because Pasha, I don't have an issue with a romantic obsession" he chuckled and got up to go stand by his lover who recoiled; sending a negative feeling coursing through McCoy's gut.

"Darlin' it's alright-"

"It's not! I don't vant zis, it…god no, not again, not like zis again" he shuddered and collapsed his head onto the wall. McCoy didn't approach him for a moment, let him vent himself out.

"It's fine, it's probably just a phase, and there is no way that…demon is still in you"

"Then vhy do I vant to-"

Chekov stopped his sentence as he whirled around to face the older man.

"…want to?"

McCoy also faltered in his speech as the Russian looked up into his dark chocolate eyes with a hazy emotion that made the southerner shiver.

"Pasha…"

Lips against his and a lithe but suddenly strong young body pressed the doctor up against the wall with a wildness that took McCoy's very breath away. Velvety lips on his as a daring little tongue slipped in and danced over his own in a heated dance that made McCoy; god forbid he ever admit it, whimper somewhat. Not only was this very forceful and sudden but the younger man had a sense of animalistic dominance that McCoy didn't have the heart to fight against so he simply let it overwhelm him as they made their way to the bed and Chekov scrambled on top of the older man with an eagerness that was shown in the frantic licks, sucks and nips around McCoy's jaw and neck.

"Pasha, wait…Jesus fucking Christ…" the doctor let dark eyes roll back with the sudden burst of pleasure as the Russian found a tantalising spot in the crook of his ear.

"Леонард" Chekov got a hold of the ear shell with somewhat unnaturally sharp teeth and tugged lightly, eliciting a shocked gasp that was swallowed by the swift return of the Russian's mouth on his. The fresh, sturdy bed didn't even creak as Chekov dug his hands into the surface and looked down on the doctor with a feral pride that caused the heartbeat of the taller man to increase tenfold. Next thing he knew his shirt was being ripped off without mercy and McCoy had no time to complain as lips attacked every faded scar on his torso; running down and over and across his body in subtle patterns that made tracing each and every one a game for Chekov.

"Aah…fuck…dammit Pasha"

The cursing earned a small bite on a tanned nipple causing McCoy to arch. As if this was really happening, as if this wild younger man was treating his body as though it was still within the prime of his youth. His lips didn't move away from the nipple, swirling the tongue around the nub with a sudden slowness that near destroyed McCoy's nerves. Chekov sighed into the ministrations; he could continue hearing the broken gasps and shattered words from the southern drawl forever. But he had other plans that the doctor soon found out about when he had sense enough to open his eyes and look down at the wandering mouth of Chekov that was nearing the top of his trouser waist band with a dangerous speed. A soft nose pressed against the dip in McCoy's hip and strong, tanned hands flew up to embed themselves in tight curly hair.

Well Chekov completely ignored that! Pulling off the pants with an unrealistic fervour and speed, his fingers were dancing along the length of McCoy's members in seconds, reducing the southerner to nothing but garbled speech and disbelief. After the Russian had, had his fun with teasing the older man's erection to the point of near pain to the dark haired man who just wanted release, the throbbing was seriously frying his nerves and his breathing was shallow and…desperate.

"Dammit Pasha, I just want to get inside you, right now"

Chekov smirked, eyelids lowered. His lips were swollen, red and shiny with a hint of precum on the edge of his mouth that he consumed with a quick flick of his tongue. His face was flushed and his hair wild. He looked gorgeous. A piece of Russian beauty, honestly, McCoy could only describe him in his head in incoherent terms of consideration and admiration. A quick dip of that delicious little tongue in the slit of the doctor's bare erection before Chekov began moving away made McCoy twitch his head to the side slightly.

He near whined at the loss of heat and pleasure but he failed to even begin complaining as Chekov placed two fingers in his mouth, swirling spit around them in a way that shouldn't be so sensual. He then placed those same two fingers before McCoy whose eyes widened as he tasted the saltiness of the other's saliva. It shouldn't have been arousing…but it fucking was. Those wet hands drew over McCoy's length, glistening and feeling so clammy and cool against the fiery temperature of his flesh. This changed when it was replaced with the slow, unbearably tight warmth of Chekov's insides. As if the kid was doing this?!

"H-Hold on, Pasha, no wait!"

To be fair this time, the Russian did pause and he looked at McCoy with feral, gleaming green eyes.

"I vant to do zis, please…vill you let me, do you vant zis?" he asked the southerner who actually found himself hesitating. Until he snapped his hips up, embedding his entire length in Chekov who gasped at the pain and tears sprang to his eyes as he clutched onto McCoy's shoulders with a vicious impact of nails and frustration.

"больно ..." Chekov yelped and the doctor shushed him, brushing fingers over his handsome face with light touches and shuttering breath. The nineteen year old was clenched around him so perfectly it was very hard not to just start pounding into him.

"It's alright darlin', you're doing fine…just tell me when to move" he whispered and leant up to kiss the nineteen year old who soon calmed down and just as the tension in the room reached a suffocating point of thickness. Chekov uttered four delicate letters.

"Move"

McCoy was slow at first, naturally so but as soon as the Russian's features contorted into that of pleasure in comparison to pain McCoy grinned and moved a bit faster, angling himself slightly in order to-

"Oh, Leonard! Oh god, yes…yes…Да, сделать…do zat again"

The Russian sounded so much sexier in his condition of fluster and helplessness and the doctor knew what he had done and aimed to hit the younger man's sweet spot over and over again until he was sobbing and leaning his head back with graceful cries, mixtures of English and his native language that caused the tight coils of heat in McCoy's stomach to burn even hotter and he moved faster.

"Yes…yes…Leo-please faster, I…"

"It's okay…just…aah"

Well conversation was becoming a big no-no as both lost breath and faltered in the precision of their once smooth pattern but it didn't matter because McCoy was coming and so was Chekov who let the white light fill his eyes as he released over the stomach of his lover as he felt warm liquid coat his insides like paint. The tantalising thrills and shivers running through his body made Chekov scream and roll his eyes back. McCoy was no better, yelling out Chekov's name and closing his eyes as he felt the satisfaction of filling the boy up. Their pattern slowed until Chekov sat limp on the doctor with lidded eyes and a parted mouth breathing hard. Even so, the swollen lips managed a smile, one that the doctor gratefully returned.

"I love you Pavel"

That was what McCoy said in the darkness as Chekov curled up to him and he froze.

"…I…I love you too…Leonard" he replied, an unstoppable beam spreading over his face as his heart fluttered uncomfortably with the sudden emotions. But it was a pleasant pain that the Russian accepted willingly.

"Just so you know, we can let your little demon friend out to play once in a while"

Chekov could practically hear the doctor grin and he pursed his lips, snuggling deeper into the old man as the moonlight spread through the thin curtains like a slight heavenly light that only lit the couple up more inside as they realised just what they had found.

A/N: THAT ENDING FLUFF JUST GOT IN THERE, I DON'T FUCKING KNOW HOW, IT WAS LIKE, RAN IN AND RAN OUT.

It has been fun, loads of fun writing this. I am so glad I managed to finish this and have you wonderful lot with me along the way. I hope you like this ending!

I struggled writing this as, guess who decided to visit? MY OVERLY SUSPICIOUS REALLY MANIPULATIVE, UNPLEASANT STEP-NAN THAT IS WHO.

But she has gone now and I have finished this rather late so will be going upstairs now to watch TOS!

-LAW09

Thanks to Killi15645: Thank you so much! I am glad you are enjoying the read!

To Who Think Fast: Don't choke! I don't mind you being whiney; I am so flattered you liked it so much! I might consider a sequel or another story based on the pair, said on the notice above so thanks again for reading!

To EllaMichelle: I am glad you think my Kirk was pretty accurate and I couldn't resist putting in about Spock giving the parent talk to McCoy. Thank you for the review!

To Kitty Bane: Thanks, I am glad you like the pace and everything! Sorry about it being the end but thanks for reading, the notice above might interest you? Thanks again!

To Sask: Our time together has been precious and I am so flattered you like my writing, the notice above should hopefully interest you and who knows, I might consider a sequel! Thanks again for reading and reviewing!

The author would like to thank you for your continued support. Your review has been posted.